Messages in this thread | | | Date | Sat, 20 Dec 1997 12:33:12 -0800 (PST) | From | "Mr. James W. Laferriere Network Engineer" <> | Subject | Re: Emergency shutdown feature |
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Hello Olaf,
ssh -l root hostname 'reboot'
But, I see you want something that will get to the kernel and the above is user-space. Why not use a ssh 'like' approach ? The packet -must- have come from a known host(s) and -must- come from a trusted 'user' . the ssh package already has this functionality, it would be nice to see this used and not rebuild the wheel . Tia
On 20 Dec 1997, Olaf Titz wrote: > > mike> Or you could plug in elcheapo joystick and run "shutdown -r now" when > > mike> both buttons are pressed for more than 5 seconds. > > Such a pattern runs the risk of being activated when someone actually > _uses_ the joystick for games. :-) But I can imagine some keyboard > tricks that are rather unlikely to be triggered by accident. > > > I know that gpm can be setup to do this... > > and init can react to key combinations too. The problem is that these are > user processes, and they won't get a chance when the scheduler is hosed. > (Which can happen with such trivial mistakes as a process running SCHED_RR > in an endless loop.) An emergency reboot like this has to be in the kernel, > called from some interrupt. > > I sometimes wanted a simple emergency reboot activated over the network. > This would supposedly be rather easy to implement. I'm thinking about the > following: a datagram has to be received (via IP is most convenient I think) > with a special type which contains e.g. the target host name and current > system time in 10 seconds granularity (to allow for clock fuzz) signed with > a secret key (MD5 suffices). The feature is activated by writing this key > into a /proc/sys entry. The cryptographic setup is to prevent trivial DOS > attacks, and this way the feature has to be activated explicitly. > > (Coding a "client" for that is left as an exercise :-) > > olaf >
, JimL +-----------------------------------------------------------------------+ | James W. Laferriere - Network Engineer - babydr@nwrain.net | | System Techniques - 25416 - 22nd S. - Kent, WA 98032 | | Give me VMS -or- Give me Linux -but- only on AXP | +-----------------------------------------------------------------------+ |-> Linux-Vax Port, Now in Progress !YAY! there's Progress To Report <-| |-> Please See http://ucnet.canberra.edu.au/~mikal/vaxlinux/home.html <-| |-> Maintainer: Michael Still mikal@blitzen.canberra.edu.au <-| +-----------------------------------------------------------------------+
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